package com.gzyj.video.utils;

import io.netty.buffer.ByteBuf;

import java.nio.charset.StandardCharsets;

/**
 * author:zhouyili (11861744@qq.com)
 */
public class ByteBufUtils {

    public static byte[] readReadableBytes(ByteBuf msg) {
        byte[] content = new byte[msg.readableBytes()];
        msg.readBytes(content);
        return content;
    }

    public static byte[] getReadableBytes(ByteBuf msg) {
        byte[] content = new byte[msg.readableBytes()];
        int start = msg.readerIndex();
        msg.getBytes(start, content);
        return content;
    }

    public static byte[] readBytes(ByteBuf buf, int length) {
        validLength(buf, length);
        byte[] content = new byte[length];
        buf.readBytes(content);
        return content;
    }

    private static void validLength(ByteBuf buf, int length) {
        int readableLength = buf.readableBytes();
        if (readableLength < length) {
            throw new RuntimeException("可读数据长度小于设定值");
        }
    }

    public static String toString(ByteBuf buf, int length) {
        validLength(buf, length);
        return buf.readCharSequence(length, StandardCharsets.ISO_8859_1).toString();
    }

    public static String toString(ByteBuf buf) {
        return toString(buf, buf.readableBytes());
    }
}
